The present invention relates to an image recording apparatus which employs an elongated photosensitive image recording medium. More particularly, the invention relates to such image recording apparatus having means for preventing a sheet cartridge from its free disassembly from a machine frame, and means for controlling disassembly timing of a sheet cartridge which stores therein the elongated photosensitive medium.
In one conventional image recording apparatus which uses a rolled and elongated photosensitive pressure sensitive recording medium, a latent image corresponding to an image of an original is formed on the photosensitive pressure sensitive recording medium at an exposure portion, and the light-exposed medium is superposed with a developer medium or sheet and are pressed together to provide a visible image on the developer sheet. Such apparatus is disclosed in, for example, U. S. Pat. No. 4,893,147.
In the conventional apparatus, a sheet cartridge which stores therein the rolled photosensitive pressure sensitive recording medium is assembled into a frame of the apparatus, and the recording medium is installed in its sheet path and is directed toward a takeup means for winding the lightexposed photosensitive pressure sensitive recording medium thereover.
However, according to the conventional device, after installation of the photosensitive pressure sensitive recording medium at its sheet path, the sheet cartridge can be detached from the frame. Therefore, the sheet cartridge may be erroneously disassembled from the frame by an operator even if wholly unexposed photosensitive pressure sensitive recording medium still remains in the sheet cartridge. Accordingly, unexposed portion of the photosensitive pressure sensitive recording medium is disadvantageously drawn out of the sheet cartridge. Therefore, when assembling the sheet cartridge into its proper location, the takeup means must be manually rotated, which requires skills for the operator.
In another conventional image recording apparatus, a front door is provided for sheet jamming treatment. In the apparatus, a light shielding plate is provided at the cartridge installing portion in order to prevent the photosensitive pressure sensitive recording sheet drawn from the cartridge from being exposed to light due to the door opening. The front door can be opened at any time, and the light shielding plate is also freely openable by an operator. Therefore, if the operator inadvertently opens the front door and the light shielding plate irrespective of the recovery of the sheet jamming, the unexposed recording medium may undergo light exposure. Consequently, such light exposed portion becomes unavailable for the image recording operation. Further, the operator may freely open the door and the light shielding plate for sheet checking, and another sheet jamming may occur due to improper disassembly of the sheet cartridge from the frame. Incidentally, a related application, commonly assigned has been filed bearing a Ser. No. 07/470,900 filed on Jan. 29, 1990.